Draw and Automatically Generate Sewing Patterns For Free Online (V2)

Not sure how to start making patterns? Do you struggle with the maths of calculating accurate middle (gusset) pieces. This is the tool for you!

This is the quickest way to generate a pattern for any sewn item that consists of a side panel and a gusset (middle piece) sewn around. Think frame bags, laptop bags, pouches, backpacks, totes, purses.

I have previously released a Inkscape extension that can automatically generate patterns from shapes drawn, such as bag side panels. Not everyone has access to or uses Inkscape, so I’m working on bringing that key functionality to an online tool.

Work in progress! Might have some bugs. Test with a paper model or scrap fabric before committing to your expensive materials.

Want to support development of more free tools?

These free tools take up a significant amount of my limited personal time so any support is appreciated 🙂

VERSION 2 (June 2025)

This version is a complete rewrite from the ground up to make it more intuitive and similar to familiar graphic design software. The UI is completely refreshed, the canvas is fully interactive, and the first work on pre-set shapes for you to start patterning from has been implemented

Please report any bugs via PayHip Contact Page

Start Designing Your Own Gear!

Open the Pattern Generator

Open Pattern Generator in a new tab

Version 1 is still available here if required, as the save files aren’t compatible between versions.

Instructions:

Drawing

Draw your shape by clicking or tapping on the canvas.

Or Generate a shape by clicking the circle or rectangle (rounded corners) button

Add gusset seams. Click a point to mark it as a seam (split in the gusset piece, a new pattern piece).

Delete points by clicking and selecting delete

Move points by clicking/tapping and dragging any point. Drag on the canvas to select multiple points

Add new points on lines by tapping/clicking anywhere along a line segment

Movement

Hold shift and click the canvas to pan. Mouse wheel to zoom

On mobile, use two fingers to move and zoom canvas.

Add seam allowance by pressing enter or click the Close Polygon button to complete the shape. A helpful 3D view also appears! You can adjust the seam allowance in the pattern generation sidebar

Scaling is adjusted by either specifying the actual real world dimensions of each grid square, or choosing a line segment and specifying the known length of that segment

Background image for tracing is added by clicking the browse button, and opacity can be adjusted. If the background image has wonky perspective, please use my free perspective correction tool before tracing. No images are uploaded to me, this all runs locally on your device.

Pattern Generation: Specify how wide you want the bag to be (use the 3D view to visualise) and the seam allowance, then click Generate Pattern (or type P).

You will now have a automatically generated pattern, ready to cut out and sew!

Printing and Assembling:

Patterns must be printed at 100% or “Actual Size” or equivalent in your printer settings. Use the scale box to check your printout before cutting fabric.

Cut along the borders and tape the borders together.

Made something cool? I’d love to see. Feel free to share your creations via the social links at the top of the page, reddit.com/r/myog or the contact form.

Known Quirks:

You can draw whatever, but doesn’t mean you can sew it. For example, patterns with sharp inwards corners you will struggle to sew. Again, test on scraps before fully committing.
Might have bugs. Test whatever you generate with a paper model or scrap fabric before committing to fabric.
Linear segments only currently. Version 2 has laid the groundwork for beziers and curves in the future. For now, just draw lots of points to simulate curves, and move the points if you need to adjust them. Your sewing accuracy will be less than the points not being a perfect curve.
Wide gussets (wider than the paper width) aren’t tiled.